Authors: MUHAMMAD ABID, JAWAD QARNI
Abstract: This paper presents a detailed computational procedure for predicting the complete thermal history including transient temperature distribution during girth welding and subsequent post weld cooling of low carbon steel pipe flange joints. Using the FE code ABAQUS, 3-dimensional non-linear heat transfer analysis is carried out to simulate gas metal arc welding (GMAW) process. ANSI Class #300 flange is used with a 6 mm thick, 200 mm long and 100 mm nominal diameter pipe. Joint type is a single `V-groove' butt joint with a 1.2 mm root opening. FORTRAN subroutine is utilized for the application of volumetric heat flux from the weld torch using Goldak's double ellipsoidal heat source model, which is based on Gaussian power density distribution. Temperature dependent thermal properties as well as phase change effects have also been accounted. Apart from comprehensive discussion on the thermal history, in-depth analysis of the axial temperature profile at four different sections on both sides of the weld joint is presented. The simulated results showed that the temperature distribution around the implemented heat source model is steady when the weld torch moves around the circumferential joint. The present simulation model can be used as a proper tool to investigate the effect of different GMAW process parameters.
Keywords: Finite element analysis (FEA), girth GMAW process, pipe-flange joints, thermal history, transient temperature distribution.
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